SOME NEW AND RARE CEPHALOPODA. 



129 



is generally attached to the sides of the mantle ; the branchial hearts are without fleshy 

 appendages ; the biliary ducts without follicular appendages ; the shell is represented 

 by two short, brittle, horny or gelatinous styles, encysted in the dorso-lateral parts of 

 the mantle. This family includes the genera Octopus, Leach, and Eledona, Leach. The 

 following is a tabular view of my classification of the Cephalopods : — 



Classis. 



Ordines. 



Tribtts. 



f OcTOPODA 



Familia 

 Nuda . . . . . 



DiBRANCHIATA < 



I Decapoda < 



TeuthidtB 



Teteabranchiata ' . 



Genera. 

 f Eledona. 

 [ Octopus. 



^^^'"'^^'^ { BefleroXn, &c. 



f Loligopsis. 

 \ Cranchia. 



fSepiola. 

 Rossia. 

 Onychoteuthis. 

 Loligo. 

 Sepioteuthis. 



J Sepiadce Sepia. 



I Belemnitida. . . . Belemnites, &c. 



l SpirulidcB Spirula. 



, . .,., f Ammonites, &c. 



[ AmmomhdcB. . . . | ^^^^y^^^^^ &c. 



' Nautilus, &c. 



\..r ,.7.j r Nautilus, 8 



^««'*^''^* \ Orthocera, 



&c. 



PLATE XXL 



Fig. 1. Cranchia scabra, dorsal aspect ; natural size. 



2. Cranchia scabra, ventral aspect ; natural size. 



3. Cranchia scabra, head, with the mantle, a, a, laid open to show the attachment 



of the funnel b, by means of the muscular membranous processes or 

 ' brides', c, c. Magnified. 



4. Head and mouth of Cranchia scabra, showing the webs, a, connecting the six 



dorsal arms ; the outer lip, b, the inner lip, c, inclosing the gaping man- 

 dibles. Magnified. 



5. A small portion of the skin of Cranchia scabra, showing the denticulate pro- 



cesses, highly magnified. 



6. Loligo laticeps, dorsal view ; natural size. 



7. Loligo laticeps, ventral view ; natural size. 



9. A sucker of one of the short arms, magnified. 



' The subdivision and grouping of the very numerous members of this order must repose entirely on a study 

 of the modifications of the shell and other enduring parts ; and I have here introduced provisionally the tvi'o 

 principal divisions as proposed by M. D'Orbigny, merely for the purpose of citing the principal genera in ex- 

 emplification of the Tetrabranchiate Order. 



s2 



